Not my experience in NE IL w/Amazon. 99% of time delivered per promised time, or before.

Sometimes, if the timing is right, I have ordered something from Amazon in the evening and had it sitting on my porch the next morning.

USPS used to be good. Questionable at best now. Like another poster here, I've tracked USPS packages to their destination point....almost, only to take off & travel thousands of miles away for some unknown reason, and then watch them return back to the real destination. This all happens with labels created by local USPS counter service. No handwriting problems.